Back to matchesWe found a matchYour institution may have rights to this item. Sign in to continue.TitleLong term variations in the frequency of polar mesospheric clouds in the Northern Hemisphere from SBUV.AuthorsShettle, E. P.; DeLand, M. T.; Thomas, G. E.; Olivero, J. J.PublicationGeophysical Research Letters, 2009, Vol 36, Issue 2, pn/aISSN0094-8276Publication typeArticleDOI10.1029/2008GL036048